This invention relates to an apparatus which semiautomatically shreds hazardous waste containers and the material contained in them and places the shredded material in disposable containers in a fail-safe manner.
Hazardous waste is typically collected at industrial facilities in 55 or 85 gallon drums or other similarly sized large containers. If this waste is to be disposed of by burning in an industrial furnace, it must first be removed from the large container and placed into smaller burnable containers, such as fuel pails, which typically hold six gallons. The contaminated drums must then be disposed of, which typically is accomplished by reducing them to small pieces in counter rotating, intermeshing blade shredders and burning the shredded pieces along with the fuel pails.
This process has several shortcomings. Transferring the hazardous material from the drums to the fire pails is not only labor intensive, but it exposes the transfer personnel to the hazardous material and its fumes. In addition, a certain amount of spillage will occur which requires cleanup and may necessitate discontinuing operations until the cleanup is completed. Also, shredding the empty drums can create sparks which may ignite the hazardous material fumes and cause rapid combustion or an explosion resulting in extensive damage.
The subject invention provides an apparatus for shredding hazardous waste drums and their contents in an enclosure with a reduced oxygen concentration, having the necessary equipment to semiautomatically handle the drums, feed them into the shredder, handle the shredded material and feed measured amounts of the shredded material into fire pails. This is accomplished in an integrated apparatus having a safety check system which prevents operation of any stage of the apparatus when the previous and subsequent stages are not yet completed. The apparatus includes two vertically arrayed shredders located in a shell with the output of the first shredder dropping directly into the second shredder. A lift raises two side-by-side drums to the top of a vertical shaft located next to the shredder shell. An ejection ram pushes the drums off of the lift into an airlock located between the shaft and the shell. The barrels are dropped from the airlock into the first shredder.
The shredded material from the second shredder drops into a collection tube containing a powered auger which transfers the material to a dispenser. The dispenser dispenses metered amounts of the material into the fire pails.
In an alternate embodiment the collection tube carries two parallel, side-by-side augers that are individually operable in either direction. This embodiment permits mixing multi-component waste into a homogeneous blend before it dispensed into the pails.
A purge system feeds inert gas into the apparatus and maintains the oxygen concentration between preset limits. In a preferred embodiment, if the oxygen concentration exceeds these limits, the apparatus is shut down and an alarm sounded.
A control system automatically processes material through the apparatus from when the drums are loaded onto the lift until the shredded material is ready to be discharged from the dispenser. The control system has built-in safeguards which ensure that the apparatus is ready for each stage of the process before that stage is allowed to occur in order to prevent accidents.
Accordingly, it is a principal object of the subject invention to provide an apparatus that semiautomatically loads hazardous waste drums into a shredder, shreds the drums and the material carried in them and feeds the shredded material to a dispenser which dispenses metered amounts of this material into disposable containers.
It is a further object of the subject invention to provide such an apparatus that provides a low oxygen environment for this operation.
It is a further object of the subject invention to provide such an apparatus having a control system that sequentially processes the drums through the apparatus one at a time.
It is a still further object of the subject invention to provide such an apparatus having a safety system that prevents any stage of the process from occurring unless the previous and subsequent stages have been completed and the apparatus is in the proper configuration for the next stage.
The foregoing and other objectives, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention taken in conjunction with the accompanying drawings.